Inflammation in Peritoneal Dialysis Patients: Effect of Obesity

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.

Verified May 2015 by Jerrold S. Levine, University of Illinois at Chicago. Recruitment status was: Recruiting

Sponsor:

University of Illinois at Chicago

ClinicalTrials.gov Identifier:

NCT01691196

First Posted: September 24, 2012

Last Update Posted: May 28, 2015

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Our study addresses the following research question: What is the role of obesity in modulating inflammation and innate immune function, as well as the overall responsiveness of innate immune cells (such as macrophages, neutrophils, and other peripheral leukocytes) in patients undergoing peritoneal dialysis?

The investigators hypothesize that obesity will lead to increased inflammation in patients undergoing peritoneal dialysis.

Peritoneal dialysate effluent (PDE) and peripheral blood will be obtained from peritoneal dialysis (PD) subjects. Levels of pro- and anti-inflammatory cytokines, chemokines, adipokines, and acute-phase reactants will be evaluated in PDE and plasma. The ability of peripheral leukocytes to respond to microbial stimuli will be studied using whole blood cultures. We predict percentage of body fat will be significantly associated with higher levels of pro-inflammatory factors both systemically and locally and with reduced ability of peripheral leukocytes to respond to microbial stimuli.

Secondary Outcome Measures:

Peritoneal macrophage subphenotype [ Time Frame: 24 hours ]

The composition of leukocytes from peritoneal dialysate effluent (PDE) will be analyzed to evaluate the absolute and relative amounts of leukocyte subclasses. The phenotype of peritoneal macrophages (pMac) will be evaluated by flow cytometry, by real time RT-PCR, and by measurement of mediators characteristic of each activation type following ex vivo culture. We predict that we will observe a significant shift from an anti- to a pro-inflammatory pMac phenotype as adiposity increases

Other Outcome Measures:

Measurement of adiposity/obesity [ Time Frame: 24 hours ]

DXA (dual energy X-ray absorptiometry) will be conducted at UIC body composition laboratory using Hologic 4500 W Elite Scan. Values from DXA scans will be primary method for evaluation of adiposity. Height and weight will be measured by nurse to calculate body mass index (BMI).

Collection of peritoneal dialysis effluent (PDE): To minimize variability, 2.5% glucose peritoneal dialysis (PD) solution and 4h dwell time will be used for all patients on test day. Immediately after collection, PDE will be chilled before further processing.

Chronic inflammation is highly prevalent in ESRD and associated with adverse outcomes. For example, chronic exposure of the peritoneal cavity to PD solution leads to induction of cytokines and other inflammatory mediators, generating peritoneal membrane inflammation which results in functional decline of ultrafiltration. Obesity is characterized by a state of chronic low-grade systemic inflammation stemming from expanded adipose tissue mass. Animal studies from our group and others suggest that obesity is associated with exacerbated prolonged inflammatory responses in the peritoneal cavity. The shifting demographic characteristics of the ESRD population, with a rise in elderly patients and those with obesity, is as a significant challenge for management of dialysis patients. Specifically, a 2-fold increase in the percentage of obese patients in the ESRD population has been reported. The caloric burden of PD glucose-containing solutions adds an additional risk for development or exacerbation of obesity and diabetes in patients using this dialysis modality. Few studies have directly evaluated the association between degree of adiposity and inflammation in PD patients. Data obtained from the proposed experiments will help clarify the connection between obesity and risk factors for cardiovascular and infectious diseases in the PD population. These data will also further our knowledge of the basic pathophysiology of both obesity and ESRD and enhance our understanding of factors involved in successful delivery of PD. Results may lead to enhanced nutritional recommendations for PD patients and/or the use of low-glucose or non-glucose alternatives, with a resultant reduction in local and/or systemic inflammation and CVD and other risk factors.

Eligibility

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Ages Eligible for Study:

18 Years and older (Adult, Senior)

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

No

Sampling Method:

Non-Probability Sample

Study Population

Patients undergoing peritoneal dialysis

Criteria

Inclusion Criteria:

> 18 years; and

peritoneal dialysis (PD) > 6 months.

Exclusion Criteria:

infectious episode within 4 weeks; and

using immunosuppressive drugs

Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01691196